This invention is a fixture for holding circuit boards to be tested in a flying probe circuit board test device.
Existing flying probe circuit board test devices use pneumatic clamps that are designed to clamp rails along the edges of circuit boards that are generally rectangular, or at least have parallel rails along substantially all of two sides of the circuit board. However, many circuit boards do not have such configuration and so cannot be rigidly held in the clamps, or they have components that are close enough to one or both edges such that they interfere with the operation of the clamps.
The inventive fixture is designed to alleviate these problems.
This invention is a fixture for holding circuit boards to be tested in a flying probe printed circuit board test device. The fixture allows the test device to be used to test different shaped and sized circuit boards, and ones with unusual component layout restrictions.
The inventive fixture is designed to be securely held in the pneumatic clamps of the existing test machines, and includes mechanical devices that are fully adjustable to accommodate virtually any size and shape circuit boards. The inventive device is coupled to the board by the board edges or using the board""s registration holes.
This invention features a universal printed circuit board fixture for a flying probe test machine that has opposed clamps, comprising a pair of members, at least one such member being movable relative to the other member, the members defining protruding portions that are adapted to be held in the opposed clamps of a flying probe test machine, and one or more engagement structures carried by each member, each such engagement structure defining an upwardly protruding pin adapted to pass through a registration hole of a printed circuit board. One or more of such engagement structures are adjustable along the length of a member, to allow the accommodation of boards of different size and shape with different locations of the registration holes.
The protruding portions of the members are preferably at the ends of the members. The fixture may further comprise means for firmly holding the engagement structures relative to the member on which they are carried. The means for firmly holding may comprise a screw and a tapped hole.
The members are preferably essentially parallel to one another. The fixture preferably further comprises a seat carried by each pin, to hold a circuit board. The seat may hold the circuit board at substantially the same height as the protruding portions.
One member may be fixed and the other may slide on a pair of rails. There are preferably two engagement structures carried by each member. The engagement structures may each define a slot that allows for adjustment of the position of the engagement structure along the length of the member.
In a more specific embodiment, the invention features a universal printed circuit board fixture for a flying probe test machine that has opposed clamps, comprising a pair of essentially parallel members wherein one member is fixed and the other slides on a pair of rails, at least one such member being movable relative to the other member, the members defining protruding portions at their ends that are adapted to be held in the opposed clamps of a flying probe test machine, at least two engagement structures carried by each member, each such engagement structure defining an upwardly protruding pin adapted to pass through a registration hole of a printed circuit board, and means for firmly holding the engagement structures relative to the member on which they are carried. One or more of such engagement structures are adjustable along the length of a member, to allow the accommodation of boards of different size and shape with different locations of the registration holes.
In this embodiment, as in the other embodiment, the engagement structures may each define a slot that allows for adjustment of the position of the engagement structure along the length of the member. The means for firmly holding may comprise a screw and a tapped hole. The fixture may further comprise a seat carried by each pin, to hold a circuit board. The seat preferably holds the circuit board at substantially the same height as the protruding portions.